I've always felt that proficiency in the command language of an OS was an essential part of being able to write code for it. I suppose it's possible to write code in a high-level language all day without knowing anything about writing batch files, but I wouldn't feel very good about my skills as a developer if I couldn't get around in my host OS's command language. I think you have to know how to write a batch file or two just to have some street cred. And I think being handy with batch files can save you some real work and make seemingly hard admin or build tasks much simpler, even with a batch file language as rickety and unwieldy as the one Windows offers.
Unix users like to brag about how superior their shell is to the Windows shell, and I have to admit there are some Unix commands I miss occasionally on Windows. One of those is the tee command. Tee allows you to direct the output from a command or batch file to the console and to a file simultaneously. I wrote a batch file that simulated tee a few years ago, and I needed it again the other day, so I dug through my bag of tricks, found it, and blew the dust off of it. Here it is for your enjoyment (save the script below as tee.cmd):
IF (%1)==() GOTO help
::Overwrite the file (W2K/XP require /Y)SET slash_y=ver ¦ find "Windows NT" >nulif ERRORLEVEL 1 set slash_y=/Y
::Overwrite the filecopy %slash_y% nul %1 >nul 2>&1
for /f "tokens=1* delims=]" %%A in ('find /V /N ""') do ( >con echo.%%B >>%1 echo.%%B)
:helpECHO.ECHO Pipe text to the console and redirect to a file simultaneouslyECHO.ECHO Usage: command | tee filename